Number

2,861

2,861 is a prime, odd.

Arithmetic Number Chen Prime Cousin Prime Deficient Number Odious Number Pernicious Number Prime Pythagorean Prime Recamán's Sequence Squarefree

Properties

Parity: Odd
Digit count: 4
Digit sum: 17
Digit product: 96
Digital root: 8
Palindrome: No
Bit width: 12 bits
Reversed: 1,682
Recamán's sequence: a(2,469) = 2,861
Square (n²): 8,185,321
Cube (n³): 23,418,203,381
Divisor count: 2
σ(n) — sum of divisors: 2,862
φ(n) — Euler's totient: 2,860

Primality

2,861 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)

1 · 2861

Aliquot sum (sum of proper divisors): 1

Factor pairs (a × b = 2,861)

1 × 2861

First multiples

2,861 · 5,722 (double) · 8,583 · 11,444 · 14,305 · 17,166 · 20,027 · 22,888 · 25,749 · 28,610

Sums & aliquot sequence

As a sum of two squares: 19² + 50²

As consecutive integers: 1,430 + 1,431

Representations

In words: two thousand eight hundred sixty-one
Ordinal: 2861st
Roman numeral: MMDCCCLXI
Binary: 101100101101
Octal: 5455
Hexadecimal: 0xB2D
Base64: Cy0=
One's complement: 62,674 (16-bit)

In other bases

ternary (3) 10220222

quaternary (4) 230231

quinary (5) 42421

senary (6) 21125

septenary (7) 11225

nonary (9) 3828

undecimal (11) 2171

duodecimal (12) 17a5

tridecimal (13) 13c1

tetradecimal (14) 1085

pentadecimal (15) cab

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
Egyptian hieroglyphic: 𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓏺
Greek (Milesian): ͵βωξαʹ
Mayan (base 20): 𝋧·𝋣·𝋡
Chinese: 二千八百六十一
Chinese (financial): 貳仟捌佰陸拾壹

In other modern scripts

Eastern Arabic ٢٨٦١ Devanagari २८६१ Bengali ২৮৬১ Tamil ௨௮௬௧ Thai ๒๘๖๑ Tibetan ༢༨༦༡ Khmer ២៨៦១ Lao ໒໘໖໑ Burmese ၂၈၆၁

Digit at this position in famous constants

π — Pi (π): Digit 2,861 = 5
e — Euler's number (e): Digit 2,861 = 0
φ — Golden ratio (φ): Digit 2,861 = 6
√2 — Pythagoras's (√2): Digit 2,861 = 8
ln 2 — Natural log of 2: Digit 2,861 = 0
γ — Euler-Mascheroni (γ): Digit 2,861 = 8

Also seen as

Prime neighborhood

Adjacent primes:

Previous prime: 2,857 (gap of 4)
Next prime: 2,879 (gap of 18)

Pair status: cousin with 2857.

Unicode codepoint

ଭ

Oriya Letter Bha

U+0B2D

Other letter (Lo)

UTF-8 encoding: E0 AC AD (3 bytes).

Lookup U+0B2D on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000B2D

RGB(0, 11, 45)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.11.45.

Address: 0.0.11.45
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.11.45

Unspecified address (0.0.0.0/8) — "this network" placeholder.

Position in π

The digit sequence 2861 first appears in π at position 1,441 of the decimal expansion (the 1,441ordinal-suffix:st digit after the integer 3).

Search range: the first 1,000,000 fractional digits of π. Any 6-digit-or-shorter string is virtually guaranteed to appear in there — the more interesting signal is the position.

Look up 2861 on Pi Search ↗